Synchronized shutter for use upon an airplane searchlight or projected gun sight



Bag, 2, 1 .9240

1,517,317 RUSSELL ET AL SYNCHRONIZED SHUTTER FOR USE UPONAN AIRPLANE SEARCHLIGHT OR PROJECTED GUN SIGHT Filed April 18. 1922 shutter mechanism for use upon an airplane atented ec. 2, I924.

HERBERT 0. RUSSELL, OF EABILIER, GALIFORNIA,,AND CHARLES LEIGH PAULUSEOF DAYTON, OHIO.

smvonnolvrmn snowman. ron use ma AN AIRPLANE smacnmen'r OR PRO? more]: GUN srcnr. a

Application sled April 18, 1922. Serial No. 555414..

To all whom it may concern:

Be it known that we, HERBERT O. RUSSELL andCHARLEs LEIGH PAULUs, citizens of the United States, residing, respectively, at Parlier and Dayton, in'the counties of Fresno and Montgomery, and States of California and Ohio, have invented certain new and useful Improvements in Synchronized Shutters for Use u on an Airplane Searchlight or Projected un Sight, of which the following is a specification.

This invention relates to a synchronized search light of a rojectinggun sight.

Tests conducte upon lights mounted in airplanes have shown that when-an attempt is made to throw the light forward through the propeller, a large proportion of this light was reflected by and from the rear surface of the rotating propeller thus making it impossible for'the observers in the machine to see anything when looking in that direction except a disk of light representmg the rotating propeller.

The ob'ect of this invention is to provide a means or' overcoming the difficulty above operates to throw a shadow on the propeller.,

Withthe above objects in View the invensame number of blades 19 as the propeller referred to "by-providing a shutter, the op' eration or rotatzonof which is synchronized with the propellerin such manner that when the propeller is in a position to receive the projected light, the shutter intervenes and tion cons'sts-in' a novel construction, combination and arrangement herein fully .described,illustrat ed and claimed.

In the accompanying drawings:

Figure 1 is a longitudinal section through the device.

Ff gure 2 is an elevation of the shutter.

Figure 3 is a diagram of the target shadow.

The instrument comprises in the present embodiment thereof a lens tube 1 containin in the rear end thereof condensing lens 21m navin-g in the forward end thereof focusing ens 3;

Between lens 2 and lens 3 is target ret'cle 4 comprisingan annular or ring opaque portion' 5 and an opaque central portion 6. When the rays are projected upon the target, the retiele 4 causes a ring-like shadow 7 to be projected upon the target and also a central dark spot or shadow 8.

To the rear end of the tube 1 there is connected a lamp casing 9containing an electric lamp 10 held by socket 11 fastened in the casing 9. Thetube 1 and easing 9 form a-housing for the (parts referred to and said to be mounted upon one which is journaled the shaft 17 of the rotaryshutter 18 having opposite two blades 19.

Each blade is of sufficient size to momen- I tarily cut olf the rays of lightbeing projected from the lens tube thereby eliminating illumination of the blades of the propeller of theaircraft and overcoming the serious objection heretofore referred to. The shaft 17 of the rotary shutter 18 may be driven by suitable means connecting the same with the 'engine of the aircraft as for example; a

flexible driving shaft 20.

The shutter 18 W11 ordinarily have the jecting apparatus for aircraft, a shutterop-;

crating in synchronism with the propeller to revent the beam from striking the propel- 2. In combination with a light beam projecting apparatus for aircraft, ashutter o'perat ng in synchronism with the propeller to prevent the beam from striking the propeller, said shutter being rotary, and being driven by the aircraft engine and at engine driven by the aircraft engine. speed.

3. In combination with alight bea-m pro- In testimony whereof we afiix our signajecting apparatus for aircraft, a shutter optures. 6 "erating in synchronism with the propeller to Y prevent the beam from striking the propel- HERBERT O. RUSSELL. ler, said shutta' being rotary and being CHARLES LEIGH PAULUS. 

